UA signee Stanley Johnson had a pair of dunks during the McDonald’s All American Game, but his biggest play was assisting on the go-ahead dunk. 

Charles Rex Arbogast / The Associated Press

CHICAGO — By the time he entered his senior year at California’s Mater Dei High School last fall, state championships were almost a yawn for Stanley Johnson.

So the Arizona Wildcats signee upped his standards a bit, and it included his supporting role in the West’s 105-102 victory in the McDonald’s All American Game on Wednesday at the United Center.

“Since I had won three in a row, the goal wasn’t just to win another state championship. I know I can do that,” Johnson said. “So I want to win every game, and that’s what we did. We did a great job.”

“Now, I’m 36-0 on the season.”

Mater Dei went 35-0, beating Oakland Bishop O’Dowd in the California top-shelf Open Division on Saturday, and Johnson picked up his first all-star win of the postseason in part by dishing the game-winning assist to co-MVP Jahlil Okafor.

Johnson had eight points and three rebounds, scoring on a pair of dunks and a pair of 18-footers, while setting up Okafor for a go-ahead dunk with 40 seconds remaining with a well-placed bounce pass.

“Once I saw (a defender), I could either make a tough runner or make a pass,” Johnson said. “I threw a little Steve Nash into him into the paint, and he finished hard. I wanted to be on the ball and make a play.”

Okafor was glad he did. The Duke-bound big man, who drew big cheers from hometown fans any time he scored, finished with 17 points and seven rebounds.

Okafor shared co-MVP honors with North Carolina-bound Justin Jackson (23 points, five rebounds), and onetime UA recruiting targets Emmanuel Mudiay (15 points) and Rashad Vaughn (14) were other high scorers for the West.

But Okafor’s dunk put the West up 103-102, and the East never led again in a game that featured 21 lead changes.

“That was not a surprise,” Okafor said. “He’s so smart, and he wants to win. He made the right play. I was open, and I could finish. All the credit goes to Stanley.”

It was also the kind of play Johnson made often during his senior year, essentially playing point guard out of necessity for Mater Dei. He had played inside early in his high school career, known for his power and athleticism around the rim. Since then, he has developed his perimeter game.

The experience, combined with his work ethic, has made Johnson even more well-regarded as a senior.

Before “you would never talk about him as his passing being a strength, but actually he’s a terrific passer,” said Southern California-based analyst Josh Gershon, who has seen Johnson for years. “He played a lot of point guard this year and, not that he was selfish before, but it’s impressive to be such a great scorer and making shots — but also by making your teammates better.”

What’s more, although Johnson missed all three of the three-point attempts, he threw two 18-footers squarely through the net — another skill he was not known for early in his high school career.

And, of course, he also added an emphatic dunk that drew a roar from the United Center crowd of 17,616 when he received a second-half alley-oop pass.

“I think I played my game,” Johnson said. “I hit open shots, went to the rim and made some plays. Being here was truly a blessing.”

More opportunities are coming, too. Johnson will play for USA Basketball in the Nike Hoop Summit next week and in the Jordan Brand Classic the week after that.

Sleep is optional.

“It’s crazy, but it’s good,” Johnson said. “You just get up and go. That’s what I’m gonna do.”